Vacuum exhaust tube for connection to marine engines



Sept.` 19,' 1950 R. x. MacARTHUR VACUUM EXHAUST TUBE FOR CONNECTION TO MARINE ENGINES Filed July 26, 1946 A INVENTOR Maf I'l/ @y ma( ATTCDRNEYS "'lf. l l

=.This invention relates v'todevices foralause .on vessels for improving `the efficiency `of operation thereof.

An'lobject of the invention is to provide!v a de- Vice which, when connected to the engines vof a vessel, will enable them f to' exhaust against a ,pressure which is less than atmospheric pressure. Another object of the invention is to provide a device, which, when installed in a vessel, l will cause a stream of water to be discharged against the propeller thereof, and in doing so, decrease or eliminate the cavitation of the propeller, decreasing the slip of the propeller and also decreasing the sternsuction of the boat.

A further object of the invention is to provide a device of the character described, which is simple in design, applicable to a variety of vessels, and effective in operation.

O-ther objects and advantages of the invention will be apparent from the following description of a preferred embodiment thereof as illustrated in the accompanying drawings, and in which,

Figure 1 is a plan view in section, of a vessel with my' improved device installed therein, and

Figure 2 is a partly broken out sectional elevation of the vessel shown in Figure 1.

Reference is now had to the drawings, in which like reference characters' denote similar parts throughout thel several views. As shown, there is a hull2 of a vessel, the approximate mold line of which is indicated by the dottedhnes 4 and 6. The vessel may be driven by means of motors 8 and IU mounted inside the hull, vthe motors being coupled' to a drive shaft for driving a propeller" l2, a rudder being shown at I4.

The motors may be of almost any type, such l which the motors exhaust, thereby making them operate much more efficiently;v

This is done in a manner as explained below.

' As shownA in the preferred example illustrated, I

provide elongated tubes' I6 and I8 which extend' the greater part'of thelength of the hull, and have open water inlet mouths at and 22 respectively, nearthebow 24 ofthe vessel. These "UNITED, STATES EW.

. y vAcUuMExrIAUsT TUBE FonooNNEcTloN 'l To MARINE ENGINES` l "Robert MacArthur, Cleveland, Ohio Appiicatioaiulyza 1946, seriiu Np. eclissil ,l n

as'the vessel moves forwardlywater `iio'wsinto heiubesd and 1.8. through their inletmovths 2U andi22, and, flows througnthev entire length of the tubes, to be discharged fromtheoutlets 26 andf28 andtowardhe propeller lf2,"'in line Withythejcentzer line ofthe propeller shaft. This resultsl in decreasing `or eliminating` the avitation ofthe propeller, decreasing the slip of the propellerf andfalsojdecreasing "the stern 'The"tube's"|6' and vfI8are'provided with constricted portions 30 and 32 so that as the Water flows through the tubes jet energy is generated, introducing a partial vacuum astern of the constrictions.. The engines 8 and l0 normally exhaust to atmosphere through exhaust pipes 34- and 36 which lead upwards into a common exhaust duct outlet pipe 38. It is apparent that the exhaust pipes 34 and 36 may be connected into the water tubes I6 and I8 substantially at locations 40 and 42 respectively as illustrated, that is, rearwardly of constrictions 30 and 32 near the point of greatest vacuum. When this is done, and check valves 44 in exhausts 34 and 36 are closed to prevent the gases from exhausting up the pipe 38, the gases are drawn into the tubes I6 and I3 through pipes 46 and 48, thereby exhausting into a region of partial vacuum, and hence operating with greater efficiency since they do not have to overcome normal atmospheric pressure while exhausting.

Check valves and 52 may also be installed in th pipes 46 and 48 to control the ow therethrough.

According to present practice, it is very essential to supply as large an amount of Water to the stern tube or tubes of a vessel as possible, espee cially with the rubber stern bearings or micarta filled stern bearings used, and for this it is common to employ a pump to supply the water. With my vacuum tube installation, water under pressure may be taken out of the tubes I6 and I8 forward of the constricted portions 30 and 32,

and piped to the stern tubes, thus eliminating the use of the said pump. Other suctions as great and asmany as desired, can be taken from the said 4tubes to supply circulating suctions, sanitary sea water supply lines, fire pump suctions, and any other required type of sea suction. This would eliminate the suction scoop commonly attached the uter hull of fast vessels ranging in size from cabin cruisers to fast battleships and cruisers. This is of particular advantage since it-eliminates the considerable drag imposed on the hull by these scoops.

The tubes disclosed are intended for installation in any designed hull, from a small gas boat to the largest battleship, wherein, by the momentum set up in the tubes by the boat moving through the water I provide a means of exhausting the propulsion engines to a vacuum instead of against atmospheric pressure, and thus avoid retarding boat speed, and hence decrease operating and instal1ationcosts.

Although I have described a preferred embodiment of my invention in specific terms, it is to be understood that various changes may be made in size, shape, materials and arrangement without departing from the spirit and scope of the invention as claimed. y ,Y

I claim:

In a boat including a hull, ascrewpropeller'at the stern thereof, and internal combustionmeans including a, pair of exhaust ports, a pair of elongated open tubes arranged in parallel spaced relation with respect to each other and supported constricted to create a partial vacuum whereby said internal combustion means may be exhausted into a pressure less than atmosphere, and conduit means having an end connected to each of said exhaust ports and the other end in communication with the restricted portion of each of said tubes.

ROBERT X, MAcARTI-IUR.

' REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS 

